I love thrifted books, so I’m always checking the book section at thrift stores, used bookstores, library sales, and little free libraries. There’s something fun about finding a forgotten hardcover or an old paperback with somebody else’s notes tucked inside.

That’s why I was caught off guard the first time I heard people were putting thrifted books in the freezer.

At first, it sounded a little ridiculous. Books belong on shelves, not next to frozen vegetables. But after hearing more collectors and secondhand shoppers talk about it online, especially on BookTok, I started to understand why people do it.

Part of buying used books is accepting that they’ve already lived through a lot before they end up in your hands. Sometimes that history is harmless, like yellowed pages or handwritten recipes tucked between chapters. Other times, it can mean dust, odors, moisture, or even tiny pests hiding where you can’t see them right away.

That’s exactly why some thrift shoppers swear by the freezer method before adding secondhand books to their shelves.

books bookstore — Image Credit: Roman Eisele, CC BY-SA 4.0, via Wikimedia Commons

Why People Are Freezing Thrifted Books

Books are made from materials such as paper, glue, cardboard, cloth, and sometimes leather. When books are stored in basements, garages, outdoor free libraries, or in humid climates, they can quietly harbor pests like booklice, silverfish, or even bedbugs, none of which are easy to spot during a quick flip-through at a thrift store.

Freezing is a simple way people are dealing with that uncertainty before the books join the rest of their collection.

How TikTok Put This on Everyone’s Radar

Many readers say they learned about freezing thrifted books on TikTok, especially through BookTok creators who regularly share secondhand finds. Short videos showing books sealed in plastic bags and placed in freezers sparked confusion, jokes, and plenty of questions.

But mixed in with the reactions were stories from people who learned the hard way, skipping the step once, then wishing they hadn’t. For some, freezing books has become as routine as washing thrifted clothes before wearing them.

How the Freezer Method Works

Most people seal books in a plastic bag, place them in the freezer for about 48 hours, and let them thaw slowly while still sealed. The cold kills most insects and larvae, helping prevent them from spreading to shelves, furniture, or other books.

It’s not about cleaning the book or changing it; it’s simply a preventative step.

When Freezing Isn’t a Good Idea

Not every book should go in the freezer. Fragile antiques, rare editions, or books with delicate bindings can be damaged by temperature changes or condensation. Those are better handled with professional care.

Freezing also doesn’t solve mold problems. Cold temperatures can pause mold growth, but they don’t remove it. Mold requires careful cleaning and proper storage.

Why People Keep Doing It Anyway

For people who love thrifted books, freezing isn’t about paranoia; it’s about preservation. As more readers discover secondhand books through thrift stores, sidewalk libraries, and social media recommendations, this small step helps protect the rest of their collection.